Process and apparatus for the production of plastic-sheathed tampons

ABSTRACT

A process is disclosed for the production of plastic-sheathed or covered tampons of fibrous organic materials, especially for feminine hygiene, wherein a fiberbody is made selected from the group consisting of unpressed and prepressed fiberbodies, a porous coating of water-insoluble plastic is sprayed or spun around the fiberbody, and the fiberbody and covering are pressed to form the tampon.

United States Patent 1191 [11] 3,784,425 Schuster Jan. 8, 1974 [54] PROCESS AND APPARATUS FOR THE 3,428,044 2/1969 Whitehead et a1 128 285 PRODUCTION OF PLASTIC-SHEATHED 5,122,???) 1338 garish; arwoo TAMPONS 3,013,558 12/1961 Leupold 128/285 [75] Inventor: Wilhelm Schuster, Frankfurt, 2,178,704 11/1939 Robinson 128/285 Germany 1 Fourness 1,932,383 10/1933 Richardson 128/285 1 Asslgneer Vereinigte api w rke Schickedanz 3,565,729 2 1971 Hartman 1. 156/167 & Co., Nurnberg, Postfach, 3,616,002 10/1971 Pacquette et a1. 156/166 Germany 22 Filed; No 8, 1971 Primary Examiner-Daniel J. Fritsgh Attorney- Isler and Ornstein [21] Appl. No.: 196,537

57 ABSTRACT [52] US. Cl 156/83, 128/270, 128/285, 1

' 156/167 156/172 A process is disclosed for the production of plastic- 5 1] Int CL 0 1332 31/14, 65 81/06, A6 13/20 sheathed or covered tampons of fiibrous organic mate- [58] Field of Search 156/83, 172, 184, rials, especially for feminine hygiene, wherein a fiber- 156/294, 278, 280, 166, 167; 128/270, 285; body is made selected from the group consisting of-un- 117/104 R 1051 1054, 140 A pressed and prepressed fiberbodies, a porous coating of water-insoluble plastic is sprayed or spun around 5 R f r Cited the fiberbody, and the fiberbody and covering are UNITED STATES PATENTS pressed to form the tampon.

3,683,912 8/1972 Olson et a1 128/285 3 Claims, 1 Drawing Figure PATENTEDJAN 8 I974 INVENTOR BY WILHELM SCHUSTER MiCQW ATTORNEYS PROCESS AND APPARATUS FOR THE PRODUCTION OF PLASTIC-SHEATHED TAMPONS This invention concerns a process for the production of plastic-sheathed tampons of fibrous, organic materials, especially for feminine hygiene, as well as an apparatus for carrying out this process.

Tampons for feminine hygiene, consisting of fibrous, organic materials, for example, cellulose wadding or the like, and which have on their surface a thin plastic film, are already known. Thus, for example, in the DT-PS 1,076,885, a process for the production of such tampons is described, in which first, in the known way, for example, by winding a cotton fleece to a rough body and then pressing, a tampon is prepared; then around its insertion end, a soft, flat line (strip) of material, made of a plastic easily soluble in water, dispersible in the body fluids, is laid, and is brought by pressure and the action of heat to cling uniformly and firmly to the tampon. As a material for the plastic film to be applied later, substances are suggested in the said patent, such as methyl cellulose, hydroxy ethyl cellulose, polyvinyl alcohol and the like. The film applied should have, as in those previously known, coatings of gelatin and the like, which have the purpose of facilitating insertion. The film should then dissolve within the body in the body fluids and thus be removed as such.

Even though such film coatings facilitate the insertion of the tampon in the body cavity, they also have several disadvantages. These disadvantages consist, first of all, of the fact that the plastic film can only be dissolved when sufficient body fluid is available. If this is not the case, as for example, at the beginning or end of the menstruation period, then the coating remains undissolved and the tampon may not be effective at all. Since in this case it retains its original hardness, it is felt by many wearers to be disturbing and consequently is rejected.

Tampons of this kind have also the disadvantage that after the dissolving of the plastic coating, they are completely uncovered and often lose their cohesion. Especially with the occurrence of much fluid, there is danger that fibers or parts of the tampon will loosen and later can no longer be removed.

From German Patent No. 831,745, a protective tampon for feminine hygiene is also known, which is distinguished by the fact that the moisture-absorbent filling, bedded in a screen-like gauze winding, which is to consist of wedding, cellulose sponge or the like, is surrounded by a closely fitting jacket of rubber or plastic, provided with holes. A similar proposal is contained in German Petty Patent 7,007,479. Such tampons have the very serious disadvantage that because of the plastic sheathing, the suction and fluid absorption power of the tampon is greatly reduced. This defect is not so much to be attributed to the fact that the plastic sheath blocks the entrance of fluid to the suction material in part, as, rather, to the fact that the unyielding sheath hinders or makes impossible the expansion of the tampon suction body. If the sheath, as would be possible in the proposal according to German Petty Patent 7,007,479, were designed correspondingly stretchable, it would lose the power, with the tampon fully saturated, of holding together completely, and again there would be the danger that fibers or parts of the absorbent body would loosen and remain in the body after removal of the tampon.

With this state of technology, the problem exists of producing a plastic-sheathed, easily inserted tampon, of which the sheath is so designed that, on the one hand, it does not hinder the expansion of the suction body, and on the other hand, holds the latter together securely, even in a very swollen condition, so that no fibers or parts can come loose from it.

According to the invention, this problem is solved by the fact that, starting with a process for the production of such tampons, in which first an unfinished piece is formed from fibrous, organic materials, such as wadding, by pressing, winding or the like, and this is further processed to a tampon by pressing and possibly heat treating. The process of the invention is distinguished by the fact that on the unpressed or pre-pressed unfinished piece is produced a close fitting, porous sheath of water-insoluble plastic, and the unfinished piece, together with the sheath, is then pressed to a tampon. In divergence from the known state of technology, therefore, the tampon is not first finish-pressed by pressure and possible heat action, and then surrounded by a close-fitting sheath, but, rather, the sheath is produced directly on the unfinished piece, and then, together with-it, pressed to a tampon. The sheath may be produced by spinning around the unfinished piece at least one plastic thread, so that there results on the unfinished piece a coccoon-like form of high porosity. However, it is also possible to produce the sheath by spraying a dissolved or melted plastic onto the unfinished piece. The concentration of the plastic as well as the duration of the spraying should be set according to the desired degree of porosity.

Surprisingly, it has been found in development work carried out by the inventor, that the porosity of a plastic sheath, produced in this way on the unfinished piece, is retained even with later pressing to a finished tampon. This is also the case when the tampon is subjected, during or after pressing, in the known way, to a heat treatment. Naturally, the temperature reached must not be so high that the sheath material begins to melt. But if these conditions, inherent in the nature of the case are observed, the pressing process will have no influence on the porosity of the sheath.

Especially advantageous, in the process according to the invention, is the fact that the sheath necessarily has the diameter of the fully expanded suction body. This has the result that, with penetration of the fluid to be absorbed into the suction body, no appreciable resistance is opposed to its expansion. On the other hand, with this process, no tensions occur in the sheath itself, so that even in the case of a very tender (fragile) sheath, there is no danger that it will tear off, and thus set free individual fibers or parts of the suction body.

By spinning or spraying around the unfinished piece with thread or drop-form plastic, according to the invention, the elements forming the sheath, thus, for example, the threads, drops or the like, will be formed just before applying on the unfinished piece itself. As variant to this, however, it is also possible to produce the porous sheath by winding the unfinished piece with at least one plastic thread, which is drawn from a spool or the like. In this case it is advantageous to dissolve or swell the surface of the plastic thread with a suitable solvent, before winding it on the unfinished piece. The thread is then laid on the unfinished piece at random,

in so-called wild winding. In this process also it is advantageous to work not only with one thread, but better with several.

As material for the water-insoluble porous sheath, the organic elastomers, especially polyether urethane, have proved especially good. Such plastics are on the market and are available with different physical properties. One type used with success by the inventor had a softening temperature of 180-192 C., a specific weight of 1.11 and a strength of 350 kp/cm The 300 percent modulus was 77 kp/cm and the stretch 600 percent. Such polyether urethanes are, as we know, resistant to hydrolysis as well as mold, and are excellent for spraying and spinning from organic solvents as well as from the melt. As solvents may be used, for example, mixtures of dioxane and acetone in the proportion of 1:1. An 8 percent solution, for example, of the resin, in this solvent mixture, may be processed by means of spinning nozzles, known per se. The spining nozzles may be so constructed that the spun thread is surrounded on all sides by a stream of gas, for example, a stream of air, which has the advantage that the solution spun out solidifies very quickly by the evaporation of the solvent, and that because of the stream of gas, a certain stretching effect is also exerted on the freshly spun thread. Such spinning processes belong to the state of technology and will therefore not be further explained here. As a source reference, you are referred, for example, to the DT-AS 1,286,682.

Instead of the polyether urethanes mentioned, other water-insoluble plastics which can be sprayed or spun, suh as polyacrylonitrile, polyacrylic acid and derivatives thereof, polyamides, polyesters and the like, may be used. Mixtures of the said substances may also be processed, while the procedure may be such that, to produce different physical properties of the porous sheath at different places on the unfinished piece, different sheath materials and/or different amounts of material may be deposited. It is also possible, and sometimes advantageous, to apply, together with the substance forming the porous sheath, lubricant on the unfinished tampon piece.

For carrying out the process of the invention, an apparatus is proposed which is distinguished by the fact that at least one holding device for the tampon unfinished piece is arranged within the range of effect of at least one spraying device. The holding device should be rotatable in relation to the spraying device, so that the unfinished piece is covered on all sides by the spray jet. It is especially advantageous when a spraying device consists of two spraying nozzles arranged in relation to each other, of which the longitudinal axes lie at least approximately on a straight line, which runs diagonally through the space filled, in the case of operation, by the tampon unfinished piece. The spraying direction of these two nozzles is opposite each other, so that it is assured that in spraying, all the places of the unfinished piece will be covered almost evenly by the spray jet.

The spraying apparatus may, as mentioned, have several spray nozzles, of which each can be connected, selectively, through separate feed lines, with the same or different sources of spraying medium. There may also be assigned to the spray nozzles, valves, controllable in each case, of which the opening times and/or opening cross section can be set separately.

For mass production of the tampons constructed according to the invention, an apparatus is proposed which is distinguished by the fact that many holding devices are so arranged on a common line (belt), chain or the like, which can be conducted in steps through the zone of action of the spraying apparatus, the spraying device being possible, preferably, to turn on and off in the same rhythm.

1 The invention will be explained in detail hereinafter with reference to the attached drawing. In this drawing is represented schematically one form of execution of the apparatus according to the invention.

The apparatus consists, first of all, of at least one holding device 1, for the unfinished piece to be sprayed (all over). This holding device may consist, for example, of the winding spike, represented in broken lines in the drawing, which has already been used for the winding up of the original wadding (batting) fleece, and thus for the preparation of the unfinished piece. This winding spike 2 may then be removed from the winding device, with the aid of a gripper, together with the ready-wound unfinished piece, and set into the holding device 1.

The holding device 1 is, in turn, connected, for example, by means of a cogwheel gear 3; 3', with a drive motor, which serves to set the unfinished piece in rotation during the sheathing. 1

The whole apparatus is so arranged that the unfinished piece 5, in case of work (action) is in the spraying range of a spraying device 6. In the example represented, this spraying device 6 consists of two mutually arranged spray nozzles 7, 7', of which the longitudinal axes 8; 8' lie, at least approximately on a striaght line, which runs diagonally through the space filled by the tampon slug 5 in the case of work (during action). Through this arrangement, it is assured that all the parts of the surface of the unfinished piece are covered by the spray cone of the spraying device 6.

The drawing shows also that each of the spray nozzles present, 7; 7', can be connected selectively, through separate feed lines 10, 10', with the same or different source(s) of spray medium, 1 1, l 1. As sources of spray medium there are indicated in the drawing the lower parts of storage tanks, in which, for example, are solutions of the resin to be sprayed, in suitable solvents. The selective connection of the feed lines 10; 10' with these spray medium sources may take place through valves 12; 13; l4; l5; 16. This valve arrangement, however, is only represented as one of various possibilities; other possibilities may be thought of and are also known.

If, instead of plastic solutions, melted substances are sprayed, then of course the spray medium sources indicated in the drawing must be replaced by other suitable devices. As such may be considered the known devices, from melt-spinning techniques, which are connected, as a rule, through short, well-insulated, possibly heated, feed lines with a so-called spinning beam. In this spinning beam are then the spinning pumps as well as one or more spinning noules.

Inthe valve arrangement indicated in the drawing, the spray nozzles 7 may be connected through the feed line 10 and the valves 14 and 16 with the spray medium source 11. In this case, the valve 13 must be closed. The spray nozzle 7' is then connected through the feed line 10' as well as thevalves 12 and 15 with the spray medium source 11'.

If both spray nozzles 7 and 7' are connected with the spray medium source 11, then valve 15 must first be closed and then the valves 12, 13, 14 and 16 opened.

If both spray nozzles are connected with the spray medium source 11', then, correspondingly, the valve 16 must be closed, and the valves 12, 13, 14 and 15 opened.

To produce the necessary pressure for the feeding (advancing) and the spraying, conveyor pumps 17 and 18 are inserted in the spray medium lines (in the example shown, directly after the valves 15 and 16), which may be designed as cogwheel pumps, for example.

The drawing shows, moreover, that to the spray nozzles 7; 7'; in each case, controllable valves 19; 19' are assigned. These valves are of known construction and are so designed that their opening times and/or opening cross sections can be set separately. This possibility of separate setting is indicated in the drawing through the symbols 20 and 20.

Having thus described my invention, I claim:

1. The method of producing plastic, porous sheathed tampons for feminine hygiene characterized by the steps of: I

l. forming a fiber body from organic fibrous materials selected from the group consisting of pressed and unpressed fibers;

2. mounting said fiber body on a support;

3. rotating said support and said body;

4. forming at least one water-insoluble plastic thread by spinning and depositing said thread on at least a portion of said body while said body is rotating to form at least a partial sheath thereon;

5. ahd subsequently pressing said fiber body and said sheath to form a compressed tampon.

2. Process according to claim 1, wherein the porous sheath is produced by winding around the fiber body at least one plastic thread dissolved or swollen on the surface.

3. process according to claim 1, wherein the sheath materials are water-insoluble, organic elastomers, preferably polyether urethanes. 

2. mounting said fiber body on a support;
 2. Process according to claim 1, wherein the porous sheath is produced by winding around the fiber body at least one plastic thread dissolved or swollen on the surface.
 3. process according to claim 1, wherein the sheath materials are water-insoluble, organic elastomers, preferably polyether urethanes.
 3. rotating said support and said body;
 4. forming at least one water-insoluble plastic thread by spinning and depositing said thread on at least a portion of said body while said body is rotating to form at least a partial sheath thereon;
 5. and subsequently pressing said fiber body and said sheath to form a compressed tampon. 